Conventionally, a telematics service for providing information service in real time is well known. The service is provided by a communication system together with a mobile body such as a vehicle. In the service, an in-vehicle communication module executes to download a map data and a POI (point of interest) data from a service center for updating a data in a navigation system, to upload a data for aggregating dialog information of an in-vehicle device to the service center, and the like with using a wireless communication network. For example, JP-A-2006-124943 teaches an in-vehicle communication module for communicating with a center via a communication line.
One of the telematics service is emergency call service, which is provided by Japan Mayday Service Co., Ltd. In the emergency call service, when the in-vehicle device executes an emergency call, the in-vehicle communication module performs data communication with the emergency call center. Here, the in-vehicle communication module has a function for performing maintenance and inspection so that the module inspects whether a function for performing the emergency call is well. When the in-vehicle communication module executes the maintenance and inspection, the emergency call center transmits information to the in-vehicle communication module. The information is information about connection destination (specifically, a URL) for the emergency call and the maintenance and inspection and information about date (i.e., switching time) at which the connection switches to the connection destination showing the information about connection destination.
The information about connection destination in the emergency call center may be changed to new information about connection destination temporally or permanently because maintenance of equipment in the emergency call center is provided, or the equipment is updated. In this case, the emergency call center notifies new connection destination information to the in-vehicle communication module, which has been maintained and inspected. The in-vehicle communication module stores “present connection destination information” and “new connection destination information” in a memory. The present connection, destination information shows the connection destination information for communicating with the emergency call center at the present time. The new connection destination information shows the next connection destination information. Further, the in-vehicle communication module also stores the switching date, at which the present connection destination information is switched to the new connection destination information. After the switching date, the module overwrites the present connection destination information with the new connection destination information, and deletes the present connection destination information, which is used before, from the memory.
However, in a conventional art, when the connection destination information of the emergency call center is temporally switched, and the new connection destination information transmitted from the emergency call center is not correct, the in-vehicle communication module cannot communicate with the emergency call center correctly after the switching date so that the module cannot perform the maintenance and inspection normally. Specifically, even when the connection destination information of the center is temporally switched, and thereby, the module switches from the new connection destination information to the previous connection destination information after a predetermined time has elapsed, the in-vehicle communication module cannot communicate with the emergency call center during a temporally switching term. Further, the in-vehicle communication module cannot communicate with the emergency call center even when the previous connection destination information is reversed after the predetermined time has elapsed. This is because the present connection destination information, which is used before, is deleted from the memory when the switching date has come in the prior art.